Updated

Novartis AG's unit Sandoz is voluntarily recalling 10 lots of its generic Introvale birth control pills after a consumer recently reported a packaging flaw.

Sandoz said in a post on its website on Tuesday that it decided on the recall after a consumer reported that white placebo tablets were mistakenly placed in the wrong row of a 13-row card.

"While the white placebo tablets can be clearly distinguished from the peach-colored active tablets, the risk of an unintended pregnancy for a patient taking the wrong tablet over several days cannot be excluded," Sandoz said, noting it is not aware of any adverse events stemming from the flaw.

The lot numbers involved in the recall are: LF00478C, LF00479C, LF00551C, LF00552C, LF00687C, LF00688C, LF00763C, LF00764C, LF00765C and LF01261C. These lots were distributed only in the United States between January 2011 and May 2012, Sandoz said.

If a patient finds a white placebo tablet in any position other than the 13th and final row, for the 13th week, she should immediately start using a non-hormonal form of contraception, according to a notice sent out on Wednesday by the U.S. Food and Drug Administration.